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Burned CDs Last 5 years Max -- Use Tape?
Lam1969 writes "Computerworld has interviewed Kurt Gerecke, an IBM storage expert and physicist who claims burned CDs only have a two to five-year lifespan, depending on the quality of the CD. From the article: "The problem is material degradation. Optical discs commonly used for burning, such as CD-R and CD-RW, have a recording surface consisting of a layer of dye that can be modified by heat to store data. The degradation process can result in the data 'shifting' on the surface and thus becoming unreadable to the laser beam." Gerecke recommends magnetic tapes to store pictures, videos and songs."
Haven't other studies confirmed much longer lifetimes in the past for CD-R? After all, we've had CD burners for longer than 2-5 years. Is this only a surprise because absolutely nobody has ever gone back and tried to read an old disc? Somehow I'm still doubtful of his conclusions.
"It's the height of ridiculousness to say for those 9 lines you get hundreds of millions."
I have CDs that have lasted 10 years with no errors. Obviously 5 years is not the maximum life. Perhaps the maximum EXPECTED life.
Ditto, but they are data CDs & pushing 7 years old. Only read problems are ones I've inflicted (scratches, etc)..
Jaysyn
There is a war going on for your mind.
We've known that CD-Rs will degrade for a long time. Hispace have recently launched a new range of CD-Rs aimed at digital photographers. These disks use 24 caret gold to help add stability to the disks. As a result, they come with a 100 year warranty.
Your porn will be around for decades after all!!
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Not only have the early deaths of CD-Rs been greatly exaggerated before, but even the lifespan of pressed CDs were (are?) hotly disputed. In the early 80's I heard all about how CDs would last forever because each play didn't degrade the quality ever so slightly like it did with cassette tapes and vinyl records. Then in the late 80's a group of researchers determined that CDs would probably only last ten years, for whatever reason.
I got my first CD-RW drive when it was a $700 2x model well over ten years ago. The first things I burned were a bootleg Tragically Hip CD and a few rented Playstation games. I still play that Hip CD and recently I dugg out my Playstation collection to use with the epsxe emulator and they all still work great, though I can't remember which of my burned games were copied when.
I have had a few CDs and DVDs go bad, but they've always been really cheap media. Even cheap CD-Rs have been ok, but I have noticed that cheap DVD-Rs can be very poor quality and sometimes the data won't last through the night. These are usually identifiable because at least half the time the data will be corrupt straight out of the burner. You don't have to spend a lot to get good media, just don't get the cheapest media you can find.
The global economy is a great thing until you feel it locally.
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From a story three years back on National Public Radio:
"The whole history of recorded sound has been a case of one technology leapfrogging over a previous one," Karr says. "But in the last few decades, the changes from vinyl to tape cassette to CD to MP3 have shortened the life span of most music collections."
But thanks to a grant from the Smolian-Giovannoni Foundation, all of these audio formats are being transferred onto 10-inch wide, 78 rpm shellac disks -- the one rock-solid format archivists have identified that works every time.
See complete article at Shellac, the Sound of the Future
Most serious photographers I know re-burn their archives every one or two years.
I have had many problems with DVDs. I've had media that degrade quickly, and also writers that cause discs to degrade quickly. Every disc I wrote in late 2003 is bad. They started going bad after only a few months (in some cases, days).
I switched both burners and media and now have no problems. However, I still do a 100% verify, and don't totally trust DVD-R. For stuff I *really* want backed up, I put a PAR2 set on the disc, and I burn both DVD and at least one CD copy for offsite.
BTW I found that some really crappy DVD-ROM drives will read almost anything. All of those hundreds of bad discs that I have? I bought a shitty CompUSA DVD-ROM drive for $35, and it will read them all, even though NO other drive I own will read them (I tried Sony, 2 NEC, 1 Pioneer and 1 Lite-On DVD-R drives, plus Teac, Pioneer DVD-ROM drives). I have NO reasonable theory why this is, but the damn thing just reads anything. I'm glad of it too. I discovered this when I realized that my shitty $40 mintek set-top DVD player would play the discs and "better" players choked, so I decided to try a crappy DVD-ROM drive. So I can now make new copies of the messed-up discs.
That's a well known idea, I was going to put here some samples of the distributed backup in action but only can find when Cringely talked about the very same concept.
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Experience with other mechanical objects stands up and asks a question.
Will the lubricant in the bearings go sticky if the drive is on a shelf and never spun up? Someone out there must have direct knowledge.
The issue is that most (most complicated, powered) machines with moving parts need occasional mild exercise.
Don't buy name brand media. They're just rebranding, and they can switch suppliers on you.
Go right to the asian source, buy from a reputable importer. I use supermediastore.com, and I buy nothing but Taiyo Yuiden media.
The place where I work has a high-speed multispindle CD-R duplication station, and goes through CD-Rs by the thousands per month. I asked a while ago and they have tried everything, and now use NOTHING but Taiyo Yuiden media also. If they have a failure, we have to ship a replacement overnight; so a single disc failure, by the time you count all the people who have to handle a complaint and the postage, can easily cost $50, so they buy what WORKS.
Anybody hear about MO (magneto optical) media? Pretty good technology. A 3.5 inch disk can store 2 GB and 5.25 inch one 9 GB. Plus their "Archival life" is 50 years. Says so on Fujitsu's web site. I think they are cool and should be more popular (would probably make it cheaper). Anybody interested look here: http://www.fcpa.com/products/mo-drives
Tapes? Tape drives? Someone is trying to sell a stock of old drives, I'll bet. My $1,300 Seagate tape drive and expensive tapes were very unreliable compared to CDs and DVDs.
CDs and DVDs stored in ziplock bags seem to last a long time.
Changes in atmosperic pressure cause other methods of storage to breathe. Eventually pollution enters. Ziplock bags don't breathe, they just expand and contract as the weather changes.
This was not a scientific test but it did give me more confidence in the media.
Anyone know where I can download an MP3 jukebox for my Vic 20?
No, but there was a program listed in Zzap! 64 once that let you play audio tapes using your Commodore 64. Type in the program, press play on tape, turn your TV's volume up, and listen to something with slightly more signal than noise.
Usually the reason why crappy DVD-Video players play back things that don't play in other players isn't because the pickup is better, but because the decoder is more tolerant of non-standard discs. Some discs that play on PCs and these cheap players just won't play on the better ones because the disc itself is not made to the proper DVD spec. Most often I've seen either improperly encoded video or missing AUDIO_TS folders. Next to that is not having the files organized properly on the disc, or the wrong file system (ISO vs UDF)
> Peers download it and keep it on their machines.
No , they don't. Not unless they really want it.
> The P2P network automatically polls for chunks and ensure redundancy by
> pushing rare pieces to clients.
Like UseNet?
> Some sort of bittorrent expect it's rather a bitpool.
Good one! You realize that Bram was working on just such a distributed file store before he decided it was a rat-hole and quit? Then a bit later he wrote BitTorrent.
That's right. I've done quite a bit of research on this, and the fact is that the dye based CD should last about 70 years if care is taken with the storage. Interestingly enough the aluminum based cd's can run into corrosion problems that the dye based cd-r aren't subject to. Most DVD-R's seem to use a high quality dye too.
I think the main issues with cd/dvd recordable media are poor burning and storage. I don't get the part about magnetic media being better, when you consider that an unused VHS tape only has a 20year shelf life before going kaput. I've see a lot of tape based media where after aging a couple years the ferrous material starts flaking off. Hmmm.
The problem is that pressing your own CDs is not cost effective in any way. It only becomes cost effective once you print many (1000 or more) identical discs. The costs per CD go down as you do more identical discs. Setting up the platter to stamp out just one disc would be extremely expensive, as well as very time consuming.
I was thinking more along the lines of someone inventing, or streamlining the process to make it cheaper.
For instance. Currently we're using lasers to burn out reflective pits on metallic dyes adhered to plastic discs.
For pressed CDs, we're not using dyes, but some metallic compound that is physically pressed into pits.
My idea would be to have the same or similar metallic compound as pressed disc, only use a stronger laser to burn out physical pits. This could be a commercial grade device used in professional shops and not for the average home consumer. Something like this could be viable could it not?
Live forever, or die trying.
ASCII is safe. JPEG is safe. Basic HTML is safe. The only problem a thousand years from now will be finding the good stuff among all the boring crap our descendents will wish we'd deleted. (Then again search engines may be smarter than we are by 2106).
Unfortunately I'm not as confident in sound and video. MPEG is pretty safe due to DVDs, other codecs I wouldn't trust for archival in the slightest.
I was thinking about this recently. The problem is that you need a really higth power laser to create a medium that lasts. If the material is inert (the nearer that I can think about are gold and glass, preferably glass), the degradation time will decrease exponentialy with the laser power*. That is good, but even then, you'll need a very powerful laser.
Things can go better if you use some kind of revelation process, like films. Then you can create higth energy recordings with a low energy laser and a chemical reaction. The problem is that inert media don't sufer chemical reactions easily, that is by definition. Other alternative is using a mechanical process. Mechanical processes with the power required to make your media last a very long time are easy to engineer, but they are not very precise. So, we end up with a low density medium.
The only thing I can see how to create a long lasting medium with is eletrical fuses. I think it is possible to design a hight density PROM chip with this characteristic, but I never saw one.
* The odds of any process happenning that will destroy your data decreases exponentialy with the energy that this process needs to happen. That is, if you use an inert material.
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